bindtag.tk

《Beginning linux programming》一书相应的源代码

#!/usr/bin/wish -f

set count 0
button .b -text "Tick(ms)"
label .ticker -textvariable count
pack .b .ticker

bind timer <ButtonPress-1> {
    set count 0
    StartTimer %W 
}
 
bind timer <ButtonRelease-1> {
    StopTimer %W 
}
 
proc StartTimer { widget } {
    global pending count
    incr count 200
    set pending [after 200 [list StartTimer $widget]]
}
 
proc StopTimer { widget } {
    global pending
    after cancel $pending
}
 
bindtags .b [linsert [bindtags .b] 0  timer]